1. Field of the Invention
This invention relates to means for controlling the casting of liquid silicon.
2. Description of the Prior Art
In the utilization of electric arc heaters for high capacity production of low cost solar grade silicon certain problems are incurred. That is particularly true where production rates of over 200 pounds per hour are anticipated. For example, means must be provided for regulating the flow of molten silicon into an ingot caster as well as for operating the flow without mechanically movable means. In addition, there is a problem of operating in a flow regulating manner at elevated temperatures. Finally, where sodium chloride is a byproduct gas in the production of liquid silicon, there is a problem of preventing this gas from contaminating the cast silicon ingot.